The present invention provides N-(3-(2-amino-6,6-difluoro-4,4a,5,6,7,7a-hexahydro-cyclopenta[e][1,3]oxazin-4-yl)-phenyl)-amides of formula I having BACE1 inhibitory activity, their manufacture, pharmaceutical compositions containing them and their use as therapeutically active substances. The active compounds of the present invention are useful in the therapeutic and/or prophylactic treatment of e.g. Alzheimers disease.本發明提供具有BACE1抑制活性之式I之N-(3-(2-胺基-6,6-二氟基-4,4a,5,6,7,7a-六氫環戊[e][1,3]-4-基)-苯基)醯胺該等製造、含該等之醫藥組合物及其作為治療活性物質之用途。本發明活性化合物可用於治療性及/或預防性治療(例如)阿茲海默氏病(Alzheimers disease)。